pennsylvania geology, v. 43, no. 2, summer 2013 geology summer 2013 ... pennsylvania’s state...

Phacops rana (Green), the State Fossil of Pennsylvania(see article on page 3). The scale is in inches.

—Photograph by John H. Barnes

Table of Contents

Editorial—One of Life’s GreatPleasuresPage 2

Reflections on Phacopsrana (Green),Pennsylvania’s StateFossilPage 3

Book Review—“Sand,” AnEntertaining andEnlightening Book1

Survey News—New EmployeePage 12

Survey News—Summer InternsInvade!Page 13

Survey News—Eat Popcorn, LearnAbout GroundwaterPage 14

An Interesting NewIdea—The SnowballEarth HypothesisPage 15

AnnouncementPage 16

A Geologic MysteryPage 17

Staff ListingPage 18

Vol. 43, No. 2 Pennsylvania Geology

EDITORIAL

One of Life’s Great PleasuresGeorge E. W. Love, State Geologist

Pennsylvania Geological Survey

Working for the Pennsylvania Geological Survey is, for meat least, one of life’s great pleasures. Let me tell you why.

We all value different things in different ways, perhaps as afunction of how we were raised; what we saw and experiencedas children; the influence of some friend or academic advisor; ormaybe because of some life-altering experience such as thatlove-at-first-sight meeting with your significant other. I myselfderive an immense amount of pleasure from my association withintelligent, interesting people whose diverse interests astoundme. This issue of Pennsylvania Geology is a case in point. Itdeals with fossil designations, snowball earth, and themetaphysical contemplation of “sand,” and allows us to share afew minutes with young, enthusiastic students who want a careerin the geologic field. What could be more rewarding?

While working for the Bureau may be “fun,” the work of the Bureau is valuable to the public at large,to the industries of Pennsylvania, and to the future of our commonwealth. The addition of a seasonedgeologist, Robin Anthony, to our Pittsburgh office demonstrates the commitment our department (theDepartment of Conservation and Natural Resources) has to continuing the mission of the Bureau, which is,in part:

To serve the citizens of Pennsylvania by . . . disseminating impartial information on the Commonwealth’sgeology, geologic resources . . . in order to contribute to the understanding, [and] wise use . . . of its . . .resources.

Ms. Anthony’s experience is a valuable resource for us as we move forward with the petroleumresources that promote our economic well-being; her studies of the characteristics of produced water willinform our efforts to mitigate any negative impacts on the environmental resources which sustain theethereal aspects of our lives here in Penn’s Woods. Geologists are fortunate that we can cross the bridgebetween natural resources as minerals to develop and exploit for our life style and natural resources as thebeauty of Mother Nature’s gifts to our tranquility and sanity.

Lastly, I want to call your attention to our “Geologic Mystery.” This is an example of the type ofactivity in which we sometimes engage. Our mission includes collecting information to contribute to theunderstanding of our Pennsylvania rocks. This little exercise will not only stimulate discussion and debate,it will focus attention on the myriad of opinions and theories we geologists have. I suspect there are several“right” answers, depending on the assumptions applied to the rock. I hope we get numerous responses, andcan summarize them in an exposé of the history of Reese Hollow. Who knows what those Reeses weredoing in the dim and distant past?

All joking aside, the Pennsylvania Geological Survey is a resource to the people of thecommonwealth. It is one that provides data and insight. The value of the survey is enhanced by therelationships our staff has with others. Please do not hesitate to engage in this little, perhaps seeminglyinsignificant, exercise. We will all benefit from our shared knowledge.

Pennsylvania Geology Summer 2013

of 19

Reflections on Phacops rana (Green),Pennsylvania’s State Fossil

John HarperPennsylvania Geological Survey, Retired

IntroductionJacob Green first described and illustrated Calymene bufo var. rana from New York in 1832. One

hundred fifty seven years later, the Pennsylvania legislature designated Green’s “variation” the officialstate fossil of Pennsylvania. What a long, strange trip it has been!

Phacops rana (cover photograph and Figure 1) is a handsome critter that can be found in theMiddle Devonian rocks cropping out in the central part of the state. It is a trilobite (pronounced TRI-lobe-ite, not TRILL-oh-bite, as I’ve heard many folks say it), a member of an extinct group ofarthropods related to insects, spiders, millipedes, crabs, and lobsters that once dominated the seafloorsof the world for hundreds of millions of years. Despite their long and remarkable history, trilobiteswent extinct at the end of the Paleozoic Era.

The General Assembly of the Commonwealth of Pennsylvania enacted House Bill 2171designating Phacops rana the official state fossil in 1988. The legislation was sponsored by EdwardBurns, then the representative from the 18th district in Bucks County, on February 8, 1988, and itbecame law on December 5 of that year. The legislation, House Bill 2171, Session of 1988, was shortand sweet; it stated:

Designating the Phacops rana, a trilobite, as the official State fossil of the Commonwealth ofPennsylvania.The General Assembly of the Commonwealth of Pennsylvania hereby enacts as follows:Section 1. Official State fossil.Phacops rana is a specific type of trilobite, a small sea creature. Trilobites were rulers of the sea duringthe Cambrian Period, 515 to 600 million years ago. Trilobites are so named because their bodies aredivided lengthwise into three parts or “lobes.” Phacops rana means “frog eyes” because of the largeholes for eyes on the fossil. Fossils of Phacops rana are found in many parts of Pennsylvania, and,therefore, the Phacops rana is selected, designated and adopted as the official State fossil of theCommonwealth of Pennsylvania.Section 2. Effective date.This act shall take effect immediately.

Burns reported in a subsequent interview (Mays, 2006) that a teacher in the Bensalem schooldistrict contacted him because the kids in his elementary class wanted to introduce a bill in Harrisburg.After meeting with the children and seeing their work, he introduced the bill in the house. The billinitially met with derision; the legislature did not want to deal with it. Even so, it was finally placed onthe agenda and passed. Burns said, “. . . of all the things I voted on in Harrisburg over the years, thatwas the bill that got me more press” (Mays, 2006).

Despite some obvious flaws in the language of the bill (e.g., Phacops is Devonian, not Cambrian,as implied), Phacops rana (Green) is the official state fossil for Pennsylvania, for good or ill. There arenumerous reasons why this trilobite is not the most appropriate ancient life form to act in that capacity.For one thing, although found within the Hamilton Group shales and limestones cropping out in central

of 19



of 19

Pennsylvania, good specimens are difficult to come by (Ellison [1965] illustrated a beautiful specimenof an enrolled P. rana from the Frame Shale Member of the Mahantango Formation in Blair County onhis Plate 18, Figures 4 and 5). Also, inasmuch as the commonwealth has a geologic period named in itshonor, would it not be more appropriate to have a Pennsylvanian-aged life form designated as the statefossil? How about either of the following:

1. A leaf or stem from one of the many plants that grew profusely in the deltaic swamps acrossthe state 300 million years ago1 (Figure 2). From these plants came the peat that was compressed intocoal, the mineral resource that made Pennsylvania famous; or

2. Worthenia tabulata (Figure 3), an elegant marine snail shell described and named by Conrad(1835) from the Brush Creek marine zone (Conemaugh Group, Glenshaw Formation) at Inclined

Figure 1. A. Phacops rana (Green), Pennsylvania’s state fossil. B. Phacops latifrons (Bronn) from Germany, the typespecies of Phacops. C. Terminology of the typical trilobite exoskeleton. Bar scales = 1 cm.

1In 1988, State Representatives Sarafini, Tigue, Cappabianc, Battisto, and Trello introduced House Bill 2362, “An Actdesignating the Alethopteris serlii, or ‘seed-fern,’ fossil as the official fossil of the Commonwealth of Pennsylvania.” Thebill was referred to the House Committee on State Government. To date, no further action has been taken, and no voteshave been cast.

of 19


Plane No. 3 on the Allegheny Portage Railroad in Cambria County. This was one of the very firstinvertebrate marine fossils described from North America.

Many other fossils come readily to mind that could have been designated as the state fossil and,similar to the aforementioned plant fossils, would have been more appropriate than the relatively rareintact Phacops rana. Some of these are:

1. Any of the numerous trilobites that can be found in the Devonian rocks of Pennsylvania (andthere are a lot of them) (Figure 4);

2. A Late Devonian fish or tetrapod from the Catskill Formation at Red Hill, Clinton County;

3. A dinosaur whose footprints can be found in the Triassic rocks of the Gettysburg area (Figure5); or

Figure 2. Typical Pennsylvanian plant fossils commonly found in the coal-bearing rocks of eastern and westernPennsylvania. A. Pecopteris Brongniart, the leaves of the marattialean fern tree Psaronius Cotta (fromEdmunds, 2002). B. Neuropteris Brongniart, the leaves of a pteridiosperm (“seed fern”) called MedullosaCotta (from Edmunds, 2002). C. Large terminal pinnule of Neuropteris Brongniart (from Hoskins and others,1983). D. Alethopteris Sternberg, the leaves of another pteridiosperm (from Edmunds, 2002). E. Portion of astem of the giant scouring rush, Calamites Suckow (from Hoskins and others, 1983). F. Annularia Sternberg,the leaves of Calamites Suckow (from Hoskins and others, 1983). All bar scales = 1 cm.

4. Any of numerous Ice Age mammal fossils found in sinkholes and ancient lake bottoms aroundthe state.

Pennsylvania’s First(?) Fossil Description

It appears that the first fossil described from Pennsylvania was a plant stem. Amos Eaton, thefamous New York naturalist of the early 1800s, published a “geological communication” in ProfessorBenjamin Silliman’s American Journal of Science and Arts in 1831 that arguably is the earliest namingand description of a fossil from the commonwealth. A Dr. Rose, of Montrose, Susquehanna County,found the specimen in sandstone on his property and sent it to Eaton. Eaton called the fossil “Crotalusreliquus or Arundo? Crotaloides.” Why the double name? Because he wasn’t certain if it representedan animal (Crotalus is a genus of snakes) or a plant (Arundo is a genus of canes). It appeared to havethe characteristics of both. Eaton (1831, p. 122) even stated, “It is true, that these may be the mineralsubstitutions for the veins of lateral leafy appendages; it is truly wonderful, that a reed should presentso many of the characteristics of the modern rattlesnake.” Lesley (1876) pointed out that the advancedknowledge of paleobotany by the late 1800s indicated that the specimen was, indeed, a plant fossil. Asany fossil collector in Pennsylvania’s coal fields will testify, Eaton’s illustration leaves no doubt that itrepresents a specimen of the scale tree, Lepidodendron (Figure 6).

Quo Vadis, Phacops rana?The first specimens of what would eventually become known as Phacops rana were originally

described by Jacob Green in 1832. Green, who graduated from the University of Pennsylvania at theage of 16, was a man of many talents; he was a lawyer and physician, a chemist and astronomer, and anaturalist with a decided bent toward paleontology. He taught chemistry, philosophy, and naturalscience at Princeton before moving on to teach at the Jefferson Medical College (now ThomasJefferson University) in Philadelphia. His father and grandfather were both theologians, so he wasbrought up in religious surroundings that caused him some trouble later in life as he tried to reconcilehis beliefs with his scientific studies (Charwat, 2009). His interest in trilobites was spurred by meetingsome of the more famous European naturalists of the time. In 1832, he published a 95-page monographon North American trilobites illustrated with colored drawings of numerous plaster casts that he hadmade, which now reside at the Paleontological Research Institution in Ithaca, N.Y. (Charwat, 2009).Over the next eight years, he published numerous reports on trilobites. One of those trilobites wasCalymene bufo var. rana.


of 19

Figure 3. Worthenia tabulata (Conrad), an elegant Pennsylvanian-aged snail commonly found in the marine zones of thelower Conemaugh Group in western Pennsylvania and contemporaneously deposited strata throughout theUnited States. A. Conrad’s (1835) original illustration. B. Modern reproduction (from Hoskins, 1999). Barscale = 1 cm.

A Phacops By Any Other Name . . .

I’ve heard many people complain that paleontologists spend too much time changing the names offossils. It seems that every paleontologist with a bent toward taxonomy has to change the generic nameof at least one critter before passing on to that great collecting locality in the sky. Why can’t they leavewell enough alone and stick with the original name, you might ask? One of my paleontologist friendsin graduate school was so annoyed by taxonomists that he told everyone he wanted his epitaph to read,“He never described a single species.”

of 19


Figure 4. Some representative Devonian trilobites that can be found in Pennsylvania. A. Odontochile micrurus (Green)from the Lower Devonian limestones of the Helderberg Group. B. Odontocephalus aegeria (Hall) from theMiddle Devonian Onondaga Limestone. C. Dechenella haldemani (Hall) from the Middle Devonian MarcellusFormation. D. Greenops boothi (Green) from the Middle Devonian Mahantango Formation. E. Dipleuradekayei (Green) from the Middle Devonian Mahantango Formation. F. Pseudodechenella rowei (Green) fromthe Middle Devonian Mahantango Formation. G. Monodechenella macrocephalus (Hall) from the MiddleDevonian Mahantango Formation. H. Constantina pulchra Cisne from the Upper Devonian (probablyChadakoin Formation). All bar scales = 1 cm.

As a whole, taxonomists (or systematists, if you want to be snobbish about it) tend to be either“splitters” or “lumpers” when it comes to describing fossil taxa. Splitters see hundreds of genera andspecies in every museum drawer, whereas lumpers see only multitudes of morphological variety withinone or a few genera or species. As someone who has dealt with the morphological conservatism ofcertain kinds of fossil snails, I probably tend to be more of a lumper than a splitter, but I also try to beobjective enough to find the middle ground. I prefer that there be a scientifically valid reason forseparating two similar fossils, rather than wanting to name a new taxon because one of the fossils islarger, or has a slightly different shape, than the other. I like to kid my paleontologist friends whospecialize in brachiopods that they tend to name a new superfamily every time they find a specimenwith one or two extra ribs on the exterior of the brachial valve. (This is, of course, just a grossexaggeration. One or two extra ribs will only rate a subfamily of brachiopods, not an entiresuperfamily!)


of 19

Figure 5. Triassic dinosaurs. A. Photograph of the fore and hind footprints of a small ornithischian dinosaur calledAtreipus preserved in sandstone at Gettysburg, Pa. The rainwater helps them stand out in the photograph. Barscale = 5 cm. B. Reconstruction of the fore and hind footprints of Atreipus as they would appear if thepreservation were better. Bar scale = 5 cm. C. Possible reconstruction of the Atreipus dinosaur (based onOlsen and Baird, 1986). Bar scale = 10 cm.

Jacob Green (1832) originally described Phacops rana as a member of the genus Calymene, acommon name for Phacops-like trilobites in the early days. New York’s great geologist EbenezerEmmons (1860) was the first to consider this species a member of the genus Phacops, which waserected by Emmrich (1839) for a German trilobite, Calymene latifrons Bronn. Since that time, Phacopshas been widely known and recognized from Devonian strata in Europe, Africa, and North America.This has not stopped paleontologists on two continents from splitting the genus into a multitude of newgenera. For example, Maximova (1972) assigned Phacops logani Hall, a common form from theLower Devonian Helderberg Group limestones, to her new genus Paciphacops, and Eldredge (1973)reassigned Phacops bombifrons Hall and Clarke from the Middle Devonian Onondaga Limestone toViaphacops Maximova, 1972.

Something similar happened to Phacops rana. Struve (1992) reexamined Phacops species fromEurope and North America and declared that P. rana (Figure 1A) and several other American speciesof Phacops were different enough from the type species, P. latifrons (Bronn) (Figure 1B), to require anew generic name. He called it Eldredgeops in honor of Niles Eldredge, the American Museum ofNatural History’s expert on trilobites. Several years ago, I asked Eldredge, who is one of the world’sleading authorities on phacopid trilobites, for his views on this name change. It was his opinion that thenew generic name was unnecessary, and that the species rana fell within the generic concept ofPhacops. I don’t know if he has changed his mind more recently or not, but the name Eldredgeopsrana seems to have become a permanent part of the paleontological literature (e.g., Whiteley andothers, 2002; Alroy, 2011).

Conclusion—What’s In a Name?

So it is with apologies to the Pennsylvania legislature and an elementary school in the Bensalemschool district of Bucks County that I must say: Eldredgeops rana is the most elegant and commontrilobite found in the Middle Devonian rocks of central Pennsylvania. It is widely distributedthroughout the Hamilton Group shales and limestones and has even been reported from the UpperDevonian rocks of New York (Whiteley and others, 2002).

of 19


Figure 6. Amos Eaton’s “Crotalus? or Arundo” from Susquehanna County, Pa. (from Eaton, 1831). This is obviously aspecimen of Lepidodendron Sternberg, a Pennsylvanian-aged lycopsid (scale tree). Inasmuch as there are noPennsylvanian rocks in Susquehanna County, the rock bearing the fossil was probably transported in by streamor ice during one of the Pleistocene glaciations.

But, regardless of scientific accuracy, personal or professional opinions, and the vagaries ofpaleontological systematics, by legislative act, Pennsylvania’s state fossil is Phacops rana, whether thepaleontological community likes it or not. Take THAT, taxonomists!

ReferencesAlroy, John, 2013, Paleobiology Database: http://paleodb.org/cgi-bin/bridge.pl (accessed June, 2013).Charwat, Pat, 2009, Treasures in our collections—Jacob Green’s trilobite casts: American Paleontologist, v. 17, no. 4.,

online supplement, http://www.museumoftheearth.org/files/pubtext/ supplements/suppl_557b.pdf (accessed June, 2013).Conrad, T. A., 1835, Description of five new species of fossil shells in the collection presented by Mr. Edward Miller to the

Geological Society: Transactions of the Geological Society of Pennsylvania, v. 1, p. 267–270 (online athttp://archive.org/stream/transactionsgeo00penngoog#page/n128/mode/2up).

Eaton, Amos, 1831, Crotalus? reliquus, or Arundo? crotaloides: American Journal of Science and Arts, v. 20, issue 1, p. 122–123.

Edmunds, W. E., 2002, Coal in Pennsylvania (2nd ed.), Pennsylvania Geological Survey, 4th ser., Educational Series 7, 28 p.

Eldredge, Niles, 1973, Systematics of Lower and Lower Middle Devonian species of the trilobite Phacops Emmrich inNorth America: Bulletin of the American Museum of Natural History, v. 151, p. 285–337 (online athttp://digitallibrary.amnh.org/dspace/handle/2246/599).

Ellison, R. L., 1965, Stratigraphy and paleontology of the Mahantango Formation in south-central Pennsylvania:Pennsylvania Geological Survey, 4th ser., General Geology Report 48, 298 p.

Emmons, Ebenezer, 1860, Manual of geology: New York, A. S. Barnes and Burr, 297 p.Emmrich, H. F., 1839, De trilobitis—Dissertatio petrefactologica quam consensu et auctoritate amplissimi philosophorum

ordinis in alma litterarum universitate Friderica Guilelma pro summis in philisophia honoribus: Berlin, TypisNietackianis, 56 p.

Green, Jacob, 1832, A monograph of the trilobites of North America, with coloured models of the species: Philadelphia,Joseph Brano, 95 p.

Hoskins, D. M., 1999, Common fossils of Pennsylvania (2nd ed.): Pennsylvania Geological Survey, 4th ser., EducationalSeries 2, 19 p.

Hoskins, D. M., Inners, J. D., and Harper, J. A., 1983, Fossil collecting in Pennsylvania (3rd ed.): Pennsylvania GeologicalSurvey, 4th ser., General Geology Report 40, 215 p.

Lesley, J. P., 1876, Historical sketch—Geological explorations in Pennsylvania and other states: Pennsylvania GeologicalSurvey, 2nd ser., Report A, 200 p.

Maximova, Z. A., 1972, New Devonian trilobites of the Phacopoidea: Paleontological Journal, v. 1, p. 78–83.Mays, Heidi, 2006, Interview with The Honorable Edward Burns (R), 18th district, Bucks County, 1973–1990:

Pennsylvania House of Representatives, Bipartisan Management Committee, Oral History Project, 35 p.,http://www.house.state.pa.us/bmc/archives/transcripts/ Burns.pdf (accessed June 2013).

Olsen, P. E., and Baird, Donald, 1986, The ichnogenus Atreipus and its significance for Triassic biostratigraphy, in Padian,Kevin, ed., The beginning of the Age of Dinosaurs—Faunal changes across the Triassic-Jurassic boundary:Cambridge, U. K., Cambridge University Press, p. 61–87.

Struve, Wolfgang, 1990, Paläozoologie III, in Ziegler, Willi, ed., Wissenschaftlicher Jahresbericht 1988/1989 desForschungsinsituts Senckenberg: Courier Forschungsinstitut Senckenberg, v. 127, p. 251–279.

Whiteley, T. E., Kloc, G. J., and Brett, C. E., 2002, Trilobites of New York—An illustrated guide: Ithaca, N.Y., CornellUniversity Press, 400 p.


of 19

of 19


BOOK REVIEW

“Sand,” An Entertaining and Enlightening Book

A book with the simple, almost boring title of“Sand” (by Michael Welland, published by theUniversity of California Press in 2009) could notpossibly be interesting. Or could it? The answer is aresounding yes! This book is eminently readable; somuch so that it was awarded the John BurroughsMedal for distinguished writing in natural history in2010. The book is sort of a geology text, and yet itis so much more.

The author was determined to cover every facetof sand that he could think of, and he did anadmirable job of doing so. He was able to makeseamless transitions from the main subjects of hischapters to interesting tidbits, stories, andnongeological subjects. For example, the readercould suddenly find himself immersed in a sectionconcerning arenophilia (sand collecting), forensicgeology, eighteenth century France, or a poem thatrelates to sand. Along the way, Welland discussedmany historical figures and how their studies relatedto sand, including Antony van Leeuwenhoek, RalphBagnold, and James Hutton.

Welland started by approaching sand grains asindividuals. He considered what sand grains are made of and the implications of “a single grain ofsand.” He then went on to consider sand grains in groups, and in this topic, he covered angle of reposeand the size distribution of sand grains, a painless introduction to sedimentology.

Next is a section on how sand behaves when water is added, including following the travels of asingle grain of sand. This example featured a grain that traveled through Pennsylvania on its way to theChesapeake Bay, and in doing so covered what rivers are like at work and how they respond to varioustypes of change.

The topic of another chapter is sand in the ocean, including a discussion of waves, tides, andbeaches, and thus of coastal geomorphology. Welland considered the origin and movement of waves,how beaches are formed and destroyed, and how the tropics differ from more temperate coastal areas.

In the section about sand in the desert, we learn about Ralph Bagnold’s accomplishments as hestudied how sand moves in this environment. One of the tangents in this chapter was an excerpt fromthe writings of Mark Twain. Another section concerned music in the dunes, a discussion of how someareas of sand dunes seem to play musical notes in certain circumstances.

of 19


How sand becomes rock is next. We are introduced to the concept of geologic time and theprinciples of historical geology. Continental drift and mountain building also get their turn. The authorconsidered tsunamis, Hurricane Katrina, and Triassic rift valleys, among other phenomena.

A whole chapter is devoted to the idea of sand art; what cultures use it and what meaning it hasfor them. The chapter included sand art in the digital age, and sand’s role in the topic of telling thefuture.

This planetwide discussion of sand concludes with an alphabetical listing, from aggregates to zengardens, of the ways in which humans use sand. These included such topics as making glass,nanotechnology, and how vineyards are influenced by the ground they grow on.

That might seem to be a good way to end the book, but there’s still more. Welland didn’t restricthis attention just to the earth. The book would not have been complete without a section about sand onother planetary bodies, and in this section, the author included discussions of sand on Titan, Mars, andVenus.

One can learn much about geology and also about humans in this enticing treatment of aseemingly simple subject. The book includes many illustrations and a section of color photographs.The stunning range of subjects considered in the book is only hinted at in this review. I highlyrecommend the book; whether you have a degree in geology or just an interest in natural history, thereis something for everyone.

—Anne B. Lutz

SURVEY NEWS

New Employee

The Bureau of Topographic and Geologic Survey welcomes its newest member of the staff, Robin Anthony(Geologic Scientist 1), to the Pittsburgh office. Robin has morethan 20 years’ experience as a petroleum geologist, first withConsolidated Natural Gas and then as an independent consultant.She also has experience as a project manager and publicationseditor in the nonprofit sector. Most recently, Robin has worked onprojects involving the management of produced water from oil andgas wells, gas storage, coalbed methane, and unconventionalreservoirs. Welcome, Robin!

of 19


Summer Interns Invade!

We always look forward to the influx of summer students, and this year is no exception. We tookadvantage of a visit by the Pittsburgh-based interns to the Middletown office by snapping a photographof 13 of the 14 students. The caption identifies each person, his or her school, and the project each isassociated with (except staff geologist Kristin Carter, second from the right in the first row). Below thatinformation is a description of the projects. Of course, “other duties as assigned” always applies!

American Association of State Geologists (AASG) Geothermal Project. In this project, internsperformed the following: (1) examined geophysical logs from oil and gas wells for relevanttemperature and depth information to develop a database of geothermal gradients across the state; (2) compiled groundwater chemistry and physical data from state, federal, and academic sources;

First row, left to right: Meiz Boozel, James Madison University, AASG Geothermal intern; Ion Simonides, AlleghenyCollege, MRCSP intern; Julianne Gmys, Marietta College, AASG Geothermal intern; Alexandria Ceschini, AlleghenyCollege, Utica Shale Consortium intern; Dilyn Stevenson, Edinboro University, MRCSP intern; Kristin Carter (staffgeologist); Christopher Oest, Temple University, MRCSP intern. Second row, left to right: Will Hoover, Oberlin College,Utica Shale Consortium intern; Susey Fleeger, Arcadia University, Great Lakes Geologic Mapping Coalition intern;Samantha Coons, Susquehanna University, Great Lakes Geologic Mapping Coalition intern; Sarah Bradley, ShippensburgUniversity, Utica Shale Consortium intern; Daniel Reese, University of Oklahoma, Great Lakes Geologic MappingCoalition intern; Matt Yoder, Millersville University, Great Lakes Geologic Mapping Coalition intern; Rebecca Brown,Wheeling Jesuit University, Great Lakes Geologic Mapping Coalition intern. Not in the photograph because she was in thefield: Dana Heston, Shippensburg University, AASG Geothermal intern.

(3) examined drilling and geophysical logs from water and scientific investigation wells; (4) assisted in the evaluation of groundwater and water well records from the Pennsylvania GroundwaterInformation System; and (5) assisted in the development of regional groundwater statistics for waterwells.

MRCSP (Midwest Regional Carbon Sequestration Partnership) Project. These interns assistedwith three main functions relative to the Bureau’s project responsibilities under Phase III of theMidwest Regional Carbon Sequestration Partnership: (1) subsurface geologic data collection,management, and interpretation; (2) petrographic/petrologic evaluations of rock thin sections and othersamples; and (3) rock-brine geochemistry evaluation. Specifically, the interns assisted the Pittsburghoffice with the collection of geologic, location, and reservoir characterization data from all partnerstates in the Appalachian, Illinois, and Michigan basins; were trained to extract and interpret geologicdata from Pennsylvania’s Wells Information System; compiled appropriate databases for use in digitalmapping and reservoir characterization work; assisted staff geologists with thin section and otheranalyses using our petrographic microscope; and assisted in the evaluation of brine geochemistry dataas it pertains to geologic sequestration calculations.

Utica Shale Consortium Project. The Utica Shale interns assisted with (1) subsurface geologic data collection, scanning, interpretation, and data entry; (2) preparation of rock cuttings and/or coresamples for laboratory analysis of total organic carbon, bitumen reflectance, mineralogy and/orporosity; (3) petrographic evaluations of rock thin sections and reflectance samples, as necessary; and(4) collection of shale outcrop samples and field trip preparatory work.

Great Lakes Geologic Mapping Coalition Project. The interns on this project updated thePennsylvania GroundWater Information System backlog for the glaciated counties of northwesternPennsylvania, including locating wells and completing data entry for partially entered well records.

of 19


Eat Popcorn, Learn About Groundwater

Bureau geologist Stuart Reese has made an interesting video for DCNR (Department OfConservation and Natural Resources) explaining the state’s groundwater resources. The video coversmany interesting facts concerning groundwater. Did you know, for example, that if all of the state’sgroundwater was pumped to the surface, it would flood the entire state to a depth of 8 feet?

The role that groundwater plays in the water cycle is examined, as are the nature of groundwater,the effects that development have on it, and the importance of protecting this valuable resource.

This video is designed for a nontechnical audience. It was produced and edited by Kirk Felix ofthe Office of Education, Communications, and Partnerships (DCNR) and written by Stuart withassistance from Gale Blackmer, Gary Fleeger, Helen Delano, and Victoria Neboga of the Bureau. Itruns for 8 minutes and can be seen online at www.youtube.com/watch?v=vT39LIUlmzo.

of 19


An Interesting New Idea—The Snowball Earth Hypothesis

Ion SimonidesPennsylvania Geological Survey Intern

This summer there were four interns working in the Mineral Resources Division at the Pittsburghoffice of the Bureau of Topographic and Geologic Survey; they are Alex Ceschini (Allegheny College’14), Julianne Gmys (Marietta College ’15), Dilyn Stevenson (Edinboro University ’16), and IonSimonides (Allegheny College ’14). In addition to working on their respective MRCSP, Utica, orgeothermal projects (see article on p. 13, “Summer interns invade!”), these interns were required to puttogether a poster presenting a geologic hypothesis of their choice and display the poster in the lobby ofthe office building.The interns didresearch into avariety of earthscience topics, andthey settled on alittle-known idea thathas been gainingpublicity in recentyears known assnowball earth. Thishypothesis interestedthe interns because itis not well known bythe public, and if it isproved, it wouldseriously affect ourunderstanding of theearth’s climatichistory.

The idea ofsnowball earth is thatduring Neoprotero-zoic time (~750–580Ma), the earthexperienced fourcycles of alternatingperiods of globalfreezing, where glaciers completely covered the earth, and rapid global warming, where huge amountsof melting caused significant sea-level rise. During the snowball earth period, the continents wereclustered around the equator, forming the hypothesized supercontinent of Rodinia. Geologic activity atthis time consisted almost exclusively of extensive glaciation and intense volcanism. These contrary

The Pittsburgh office interns showing off their poster, which highlights the snowball earthhypothesis. Front left, Dilyn Stevenson; front right, Alex Ceschini; back left, Julianne Gmys;back right, Ion Simonides.

of 19


processes dominated earth’s Neoproterozoic climate and defined the glaciation-melting cycles ofsnowball earth.

The freezing periods of snowball earth could have been triggered by high volumes of volcanic ashthat clouded the atmosphere, preventing solar radiation from warming the planet and starting a volcanicwinter. In addition to volcanic ash, glaciers have a high albedo and would have caused solar light toreflect off the earth’s surface instead of being absorbed. A volcanic winter combined with the albedo ofexisting glaciers prevented solar radiation from reaching the earth and created a positive feedback loopthat caused global temperatures to plummet. As global temperatures decreased, glaciers grew to cover alarge portion of the earth’s surface; the precise percentage that they might have covered is still heavilydebated today. Over hundreds of thousands of years, greenhouse gases built up in the atmosphere to thepoint where a rapid climatic reversal occurred and global temperatures began to rise. As continentalglaciers melted, they released huge volumes of water, which caused rapid sea level rise and climaticchanges throughout the globe.

Some hard evidence that supports the snowball earth hypothesis has been found in Neoproterozoicsedimentary rocks in locations around the world from Namibia to Australia to China to the UnitedStates. These locations are all known to have existed within tropical latitudes during theNeoproterozoic, yet geologists have found extensive glacial tillite deposits dating from that geologictime period at these locales. In addition, mixed in with the glacial till are unusual deposits of iron-richrocks that only could have formed in an anoxic atmosphere. Conformably overlying the glacial tillitesare beds of cap carbonates that reflect the rapid melting, sea-level rise, and climatic changes thatcharacterized the switch between freezing and warming in the snowball earth cycles.

A major component of the snowball earth hypothesis is that simple single-celled organismssurvived the frozen climate in confined areas of open water or in close proximity to volcanic hotsprings where they had access to sunlight and the necessary nutrients to support life. After snowballearth ended about 580 Ma, these single-celled organisms evolved, and multicellular life exploded as theCambrian period began.

ANNOUNCEMENTThe 78th Annual Field Conference of Pennsylvania Geologists, “A Tale of Two Provinces: the

Nippenose Valley and Route 15 Corridor,” will take place on September 26 through 28, 2013. Pre-conference trips will be held on Thursday, September 26, and the main field trip will occur on Fridayand Saturday, September 27 and 28. The headquarters hotel is the Holiday Inn in Williamsport, Pa.

The conference attendees will explore two areas. On day one, they will examine the GreatAmphitheater of Pennsylvania, the Nippenose Valley of Lycoming and Clinton Counties, inside andout. The floor of this breached anticline exposes Middle to Upper Ordovician Bellefonte throughReedsville Formations. Just outside of the amphitheater are great exposures of the Marcellus, Tully,and Mifflintown. On day two, the geologists will travel along the U.S. Route 15 corridor. There theywill examine excellent exposures of the stratigraphic succession from the Devonian Brallier/Harrell/Lock Haven into the Pennsylvanian Bloss coal complex of Pottsville/Allegheny age, only to returnback to the Lock Haven. It will be a wild roller coaster ride from Williamsport to the New York borderas they cross six “time zones” trying to figure out if it is half past the Devonian or a quarter after theMississippian. For more information and registration materials, visit the conference website athttp://fcopg.org/.

of 19

A GEOLOGIC MYSTERYOne can frequently discover interesting-looking rocks in Pennsylvania. Many times, we know

immediately what they are; at other times, we can only guess. Staff geologist Stuart Reese discoveredthe rock that is pictured here on the family farm in Reese Hollow, Centre County, probably a sandstonefrom the Lock Haven Formation. Its origin is something of a mystery, and we present it here for yourperusal and suggestions as to what it might be.

Several geologists, with diverse backgrounds and training, have inspected the rock, and a numberof hypotheses have already been presented. Two of our favorite hypotheses are the following: (1) therock contains Liesegang rings (colored bands of cement that cut across bedding), and (2) the rockconsists of boxwork structures that had soft-sediment loads deposited within each box cavity, similar torocks on Mars whose image can be seen at http://spaceref.com/mars/curiousmars-box-shaped-martian-features-and-deep-water-lake-deposits-offer-new-rover-destinations.html.

Now it is your turn! We will consider publishing the most interesting comments from our readersin the next issue. Please send your comments to [email protected]. We look forward to amultitude of explanations.


of 19

Department of Conservation and Natural ResourcesBureau of Topographic and Geologic Survey

Main Headquarters3240 Schoolhouse Road

Middletown, PA 17057–3534Phone: 717–702–2017 | FAX: 717–702–2065

Pittsburgh Office400 Waterfront Drive

Pittsburgh, PA 15222–4745Phone: 412–442–4235 | FAX: 412–442–4298

Director and State GeologistGeorge E. W. Love, P. G. 717–702–2017

Administrative ServicesConnie F. Cross 717–702–2054Elizabeth C. Lyon 717–702–2063Jody L. Rebuck 717–702–2073

GEOLOGIC AND GEOGRAPHIC INFORMATION SERVICESMichael E. Moore, P.G. 717–702–2024

PAMAP and Public OutreachHelen L. Delano, P.G. 717–702–2031GIS ServicesMark A. Brown 717–702–2077Caron E. O’Neil, P.G. 717–702–2042Thomas G. Whitfield, P.G. 717–702–2023

IT and Database ServicesSandipkumar P. Patel 717–702–4277Mark A. Dornes 717–702–4278Pedro A. Forero 412–442–5826Library ServicesJody L. Smale 717–702–2020

GEOLOGIC MAPPINGGale C. Blackmer, P.G. 717–702–2032

Stratigraphic StudiesGary M. Fleeger, P.G. 717–702–2045Rose-Anna Behr, P.G. 717–702–2035Clifford H. Dodge, P.G. 717–702–2036Antonette K. Markowski, P.G. 717–702–2038James R. Shaulis, P.G. 717–702–2037

Groundwater and Environmental GeologyStuart O. Reese, P.G. 717–702–2028Aaron D. Bierly 717–702–2034Kristen L. Hand 717–702–2046William E. Kochanov, P.G. 717–702–2033Victoria V. Neboga 717–702–2026

MINERAL RESOURCESKristin M. Carter, P.G. 412–442–4234

Mineral Resource AnalysisJohn H. Barnes, P.G. 717–702–2025Leonard J. Lentz, P.G. 717–702–2040John C. Neubaum 717–702–2039Stephen G. Shank, P.G. 717–702–2021

Petroleum and Subsurface GeologyRobin V. Anthony 412–442–4295Lynn J. Levino 412–442–4299Katherine W. Schmid 412–442–4232

DIRECTOR’S OFFICE


of 19


PENNSYLVANIA GEOLOGY is published quarterly by theBureau of Topographic and Geologic Survey

Department of Conservation and Natural Resources3240 Schoolhouse Road, Middletown, PA 17057–3534.

This edition’s editor: Anne Lutz.

Links to websites were valid as of the date of release of this issue.

Contributed articles are welcome.Guidelines for manuscript preparation may be obtained at

www.dcnr.state.pa.us/topogeo/publications/pageolonline/pageoolguide/index.htm.

To subscribe, send an email to [email protected].

PEN

NS

YLVAN

IAGEOLOGICA

LS

UR

VEY

E S T. 1 8 3 6

COMMONWEALTH OF PENNSYLVANIATom Corbett, Governor

DEPARTMENT OF CONSERVATION AND NATURAL RESOURCESEllen Ferretti, Acting Secretary

OFFICE OF CONSERVATION AND TECHNICAL SERVICESCindy Adams Dunn, Deputy Secretary

BUREAU OF TOPOGRAPHIC AND GEOLOGIC SURVEYGeorge E. W. Love, Director

Bureau website: www.dcnr.state.pa.us/topogeo/index.aspxDCNR website: www.dcnr.state.pa.us/index.aspx

Pennsylvania home page: www.pa.gov

pennsylvania geology, v. 43, no. 2, summer 2013 geology summer 2013 ... pennsylvania’s state...

Documents